Question

tan 69 + tan 66 + 1 =tan 69 tan 66​

Answer 1

Answer:

Step-by-step explanation:

-1 = tan 135° = tan(69° + 66°)=

(tan 69° + tan 66°) / (1 - tan 69°tan66°)

Thus

tan 69° + tan 66° = tan 69°tan 66° - 1

and therefore

tan 69° + tan 66° + 1 = tan 69°tan66°